Clamping receptacle

ABSTRACT

A receptacle for confining circuit cards to different locations within a housing and that has a frame is provided. The frame has an array of slots, each containing one of the circuit cards. In one embodiment, the receptacle has a cam that is selectively engageable with the frame for clamping the circuit cards within the frame. In another embodiment, a shaft is rotatably attached to the receptacle. The shaft has a head at one end and a nut opposite the head. A resilient element is disposed on the shaft between the head and the nut. The resilient element is axially compressible between the head and nut to bulge generally perpendicularly to the axial direction into engagement with the frame for clamping the circuit cards within the frame.

CROSS RELATED APPLICATION

[0001] This application is related to co-pending application Ser. No.______ (Attorney Docket No. 100.204US01) entitled CLAMPING CASE andfiled on even date herewith.

TECHNICAL FIELD

[0002] The present invention relates generally to the field ofreceptacles that contain circuit cards and, in particular, toreceptacles that clamp circuit cards within them.

BACKGROUND

[0003] Environmentally protected housings are used in a wide variety ofapplications, including containing and protecting electronic componentsof the type used for transferring signals over long distances. Forexample, the telecommunications industry transfers signals overtransmission lines. If the signal is transferred over a long distance,the signal may be too weak by the time it reaches its destination to beuseful. Consequently, electronic circuits are used to detect, clean up,and amplify a weak signal for retransmission through another length oftransmission line. These electronic circuits are often deployed inenvironmentally protected housings located above and below ground.

[0004] Increased demands on the telecommunications industry, such as theadvent of HDSL, HDSL2, SHDSL, etc., to meet the increasing needs ofinternet subscribers has resulted in the need to transfer more andstronger electrical signals over greater distances. One way ofaccomplishing this is to amplify the signals using electronic circuitcards deployed in environmentally protected housings. To meet the needfor transferring stronger electrical signals over greater distances,electronic circuit cards having higher amplification capabilities, andthus greater heat dissipation rates, than the past generations ofcircuit cards are frequently used.

[0005] Many of the environmentally protected housings use cases, orreceptacles, to confine circuit cards to different locations within thehousings. Typically, these receptacles are thermally conducting and arethermally coupled to the housing to increase the heat transfer from thecircuit cards. However, in many instances, gaps exist between thereceptacles and the circuit cards. These gaps produce relatively largethermal resistances and severely limit heat transfer from the circuitcards. In many instances, this results in thermal failure of the circuitcards.

[0006] For the reasons stated above, and for other reasons stated belowwhich will become apparent to those skilled in the art upon reading andunderstanding the present specification, there is a need in the art foreliminating gaps that exist between circuit cards and the receptaclesthat confine these circuit cards to different locations within ahousing.

SUMMARY

[0007] The above-mentioned problems with gaps that exist between circuitcards and the receptacles that confine these circuit cards to differentlocations within a housing and other problems are addressed byembodiments of the present invention and will be understood by readingand studying the following specification. Embodiments of the presentinvention provide receptacles that clamp circuit cards within them toimprove the thermal contact between the circuit cards and thereceptacles.

[0008] More particularly, in one embodiment, a receptacle for confiningcircuit cards to different locations within a housing and that has aframe is provided. The frame has an array of slots, each containing oneof the circuit cards. The receptacle has a cam that is selectivelyengageable with the frame for clamping the circuit cards within theframe.

[0009] In another embodiment, a receptacle for confining circuit cardsto different locations within a housing and that has a frame isprovided. The frame has an array of slots, each containing one of thecircuit cards. A shaft is rotatably attached to the receptacle. Theshaft has a head at one end and a nut opposite the head. A resilientelement is disposed on the shaft between the head and the nut. Theresilient element is axially compressible between the head and nut tobulge generally perpendicularly to the axial direction into engagementwith the frame for clamping the circuit cards within the frame.

[0010] Other embodiments are described and claimed.

BRIEF DESCRIPTION OF THE DRAWINGS

[0011]FIG. 1 illustrates an environmentally protected housing accordingto the teachings of the present invention.

[0012]FIG. 2 is an enlarged illustration of a circuit card of the typetypically housed in environmentally protected housings.

[0013]FIG. 3 is a top view of an embodiment of a case of the presentinvention for confining circuit cards to different locations within anenvironmentally protected housing.

[0014]FIG. 4 is a top view of an embodiment of a case of the presentinvention that uses a wedge to clamp circuit cards within the case.

[0015]FIG. 5 is a side view of an embodiment of the wedge of FIG. 4taken along the line 5-5 of FIG. 4.

[0016]FIG. 6 is a side view of an embodiment of the wedge in FIGS. 4 and5 taken line 6-6 of FIG. 5.

[0017]FIG. 7 is a top view of another embodiment of a case of thepresent invention that uses a wedge for clamping a circuit card withinthe case.

[0018]FIG. 8 is a top view of an embodiment of a case of the presentinvention that uses a cam to clamp circuit cards within the case.

[0019]FIG. 9 is a side view illustrating an embodiment of a cam used forclamping circuit cards within a case.

[0020]FIG. 10 is an enlarged view of a cam.

[0021]FIG. 11 is a side view illustrating another embodiment of a camused for clamping circuit cards within a case.

[0022]FIG. 12 is an isometric view of an embodiment of a device thatuses resilient elements for clamping circuit cards within a case.

[0023]FIG. 13 is a front view of FIG. 12.

[0024]FIG. 14 is a side view of resilient elements engaging a circuitcard.

[0025]FIG. 15 is a top view of another embodiment of a case of thepresent invention that uses a cam for clamping a circuit card within thecase.

[0026]FIG. 16 is a top view of an embodiment of a case of the presentinvention that has a frame and that uses cams for clamping severalcircuit cards within the frame.

[0027]FIG. 17 is an enlarged view of region 1675 of FIG. 16.

[0028]FIG. 18 is a top view of an embodiment of a case of the presentinvention that has a pair of frames and that uses cams for clampingseveral circuit cards within the frames.

[0029]FIG. 19 is an exploded isometric view of an embodiment of a caseof the present invention that has a pair of frames and that usesresilient elements for clamping several circuit cards within the frames.

[0030]FIG. 20 is an isometric view illustrating an embodiment of a casepositioned within a housing.

DETAILED DESCRIPTION

[0031] In the following detailed description, reference is made to theaccompanying drawings that form a part hereof, and in which is shown byway of illustration specific illustrative embodiments in which theinvention may be practiced. These embodiments are described insufficient detail to enable those skilled in the art to practice theinvention, and it is to be understood that other embodiments may beutilized and that logical, mechanical and electrical changes may be madewithout departing from the spirit and scope of the present invention.The following detailed description is, therefore, not to be taken in alimiting sense.

[0032]FIG. 1 shows an environmentally protected housing 100 according tothe teachings of the present invention. Housing 100 has several cases102 ₁ to 102 _(N) that are thermally coupled to the interior surface ofwall 104 of housing 100. Each case 102 ₁ to 102 _(N) is adapted toreceive either a single circuit card, such as circuit card 106, or apair of circuit cards, such as circuit cards 108 a and 108 b .

[0033]FIG. 2 is an enlarged view of a circuit card, such as circuit card106, 108 a, or 108 b. In some instances, circuit card 106, 108 a, or 108b includes a thermally conducting case 110 that encloses circuit board112. Circuit board 112 includes heat-dissipating components 114 that arefrequently thermally coupled to thermally conducting case 110 by athermal interface material 116.

[0034]FIG. 3 is an enlarged top view of a case 102 containing a pair ofcircuit cards 108 a and 108 b. Case 102 has end walls 118 and 120,sidewalls 122 and 124, and partition 126 that are typically fabricatedfrom a thermally conducting material such as aluminum, copper, brass,bronze, or the like. Case 102 is thermally coupled at end wall 118 tothe interior surface of wall 104 of housing 100 by a heat-sink device128 that conforms to the contour of the interior surface of wall 104. Inone embodiment heat-sink device 128 is a solid block of material havingthermal properties suitable for heat sinks, e.g., copper, aluminum,brass, bronze, or the like.

[0035] Normally, relatively intimate thermal contact exists betweencircuit cards 108 a and 108 b and sidewalls 122 and 124, enabling aportion of the heat dissipated by circuit cards 108 a and 108 b to betransferred to sidewalls 122 and 124. This portion of the heat is thenconducted through sidewalls 122 and 124 into heat-sink device 128.

[0036] On the other hand, gaps 130 and 132 respectively exist betweencircuit cards 108 a and 108 b and partition 126, and gaps 134 and 136respectively exist between circuit cards 108 a and 108 b and end walls118 and 120, as shown in FIG. 3. Another portion of the heat dissipatedby circuit card 108 a is conducted and radiated to partition 126 and endwall 118 across the gaps 130 and 134, respectively. Another portion ofthe heat dissipated by circuit card 108 b is conducted and radiated topartition 126 and end wall 120 across the gaps 132 and 136,respectively. Heat conducted and radiated to end wall 118 is conductedthrough end wall 118 into heat-sink device 128. Heat conducted andradiated to partition 126 and end wall 120 is respectively conductedthrough partition 126 and end wall 120 into sidewalls 122 and 124, whichconduct the heat to heat-sink device 128.

[0037] Unfortunately, the respective gaps produce relatively largethermal resistances and severely limit the total heat transfer fromcircuit cards 108 a and 108 b to case 102. In many instances, thisresults in thermal failure of circuit cards 108 a and 108 b.

[0038] Embodiments of the present invention provide cases, orreceptacles, that clamp circuit cards within them to improve the thermalcontact between the circuit cards and the cases. This substantiallyincreases the heat transfer from circuit cards relative to the heattransfer from circuit cards that occurs when the circuit cards are notclamped within the receptacles, thus reducing the risk of thermalfailure.

[0039] Case 400, illustrated in FIGS. 4-6, is one embodiment of thepresent invention. FIG. 4 is a top view of case 400, FIG. 5 a side viewtaken along the line 5-5 in FIG. 4, and FIG. 6 a view taken along theline 6-6 of FIG. 4. Embodiments of the present invention provide casesthat clamp circuit cards within them to improve the thermal contactbetween the circuit cards and the cases. Case 400 is used to confinecircuit cards, e.g., circuit cards 408 a and 408 b to particularlocations within an environmentally protected housing, e.g.,environmentally protected housing 401. In one embodiment, circuit cards408 a and 408 b are similar to circuit cards 108 a and 108 b andenvironmentally protected housing 401 is similar to housing 100. In oneembodiment, case 400 confines circuit cards 408 a and 408 b to alocation adjacent a wall 402 of environmentally protected housing 401.In another embodiment, a heat-sink device, such as heat-sink device 403,thermally couples case 400 to an interior surface of wall 402. In oneembodiment, heat-sink device 403 is a solid block of material havingthermal properties suitable for heat sinks, .e.g., copper, aluminum,brass, bronze, or the like.

[0040] Case 400 has end walls 404 and 406, sidewalls 409 and 410, andpartition 412. End walls 404 and 406, sidewalls 409 and 410, andpartition 412, in one embodiment, are fabricated from any thermallyconducting material, such as aluminum, copper, brass, bronze, or thelike. Partition 412 divides case 400 into slots 414 and 416 thatrespectively contain circuit cards 408 a and 408 b.

[0041] Partition 412, in one embodiment, is in slidable contact withsidewalls 409 and 410 and can slide toward end walls 404 and 406,respectively. Circuit cards 408 a and 408 b, in another embodiment, arein slidable contact with sidewalls 409 and 410 and can slide toward endwalls 404 and 406, respectively. In other embodiments, thermallyconducting grease is disposed between partition 412 and sidewalls 409and 410 and/or between circuit cards 408 a and 408 b and sidewalls 409and 410. The thermally conducting grease increases the thermal contact,and thus the heat transfer, between the partition 412 and sidewalls 409and 410 and/or between circuit cards 408 a and 408 b and sidewalls 409and 410. When circuit cards 408 a and 408 b are respectively insertedinto slots 414 and 416, gaps 418 and 420 respectively exist betweencircuit cards 408 a and 408 b and partition 412 and gaps 422 and 424respectively exist between circuit cards 408 a and 408 b and end walls404 and 406, as shown in FIG. 4.

[0042] Case 400 includes wedge 428 insertable into gap 424. Wedge 428,in one embodiment, is fabricated from nylon, plastic, metal, or thelike. In another embodiment, wedge 428 has a tab 430, and in otherembodiments, an aperture 432 passes through tab 430, as shown in FIGS.4-6. Tab 430 and aperture 432 facilitate insertion and removal of wedge428 respectively into and from gap 424.

[0043] Wedge 428 is pressed into gap 424, causing wedge 428 to engageand to exert a force on circuit card 408 b. The force slides circuitcard 408 b into contact with partition 412. Circuit card 408 b exerts aforce on partition 412 that slides partition 412 into contact withcircuit card 408 a. Partition 412 exerts a force on circuit card 408 athat slides circuit card 408 a, in one embodiment, into contact with endwall 404. This respectively closes gaps 420, 418, and 422 and clampscircuit card 408 a, partition 412, circuit card 408 b, and end wall 404in direct thermal contact.

[0044] Direct thermal contact between partition 412 and circuit cards408 a and 408 b substantially increases the heat transfer from circuitcards 408 a and 408 b to partition 412 relative to the heat transferthat occurs if gaps 418 and 420 are present. Similarly, direct thermalcontact between end wall 404 and circuit card 408 a substantiallyincreases the heat transfer from circuit card 408 a to end wall 404relative to the heat transfer that occurs if gap 422 is present.Consequently, this increases the total heat transfer from circuit cards408 a and 408 b to case 400, reducing the risk of thermal failure.

[0045]FIG. 7 shows case 700, another embodiment of the presentinvention. Case 700 is used to a confine circuit card, e.g., circuitcard 706, to a particular location with in an environmentally protectedhousing, e.g., environmentally protected housing 701. In one embodiment,circuit card 706 is similar to circuit card 106 and environmentallyprotected housing 701 is similar to housing 100. In another embodiment,case 700 confines circuit card 706 to a location adjacent a wall 702 ofenvironmentally protected housing 701. In other embodiments, a heat-sinkdevice, such as heat-sink device 703, thermally couples case 700 to aninterior surface of wall 702. Heat-sink device 703, in one embodiment,is a solid block of material having thermal properties suitable for heatsinks, e.g., copper, aluminum, brass, bronze, or the like.

[0046] Case 700 has end walls 704 and 705 and sidewalls 708 and 710. Inone embodiment, end walls 704 and 705 and sidewalls 708 and 710 arefabricated from any thermally conducting material, such as aluminum,copper, brass, bronze, or the like. Case 700 defines a slot 712 thatreceives a circuit card 706. Circuit card 706, in one embodiment, is inslidable contact with sidewalls 708 and 710 and can slide toward endwalls 704 and 705, respectively. In one embodiment, thermally conductinggrease is disposed between circuit card 706 and sidewalls 708 and 710.When circuit card 706 is inserted into slot 712, gaps 714 and 716respectively exist between circuit card 706 and end walls 704 and 705.

[0047] Case 700 includes wedge 728. Wedge 728 is pressed into gap 716,causing wedge 728 to engage and to exert a force on circuit card 706.The force, in one embodiment, slides circuit card 706 into directcontact with end wall 704, thereby closing gap 714 to clamp circuit card706 and end wall 704 in direct thermal contact. In one embodiment, wedge728 is as described for wedge 428 above.

[0048]FIG. 8 illustrates case 800, another embodiment of the presentinvention. Elements that are common to FIGS. 4 and 8 are numbered as inFIG. 4 and are as described above. Case 800 includes a cam 810 that isdisposed within gap 424 between end wall 406 and circuit card 408 b.

[0049] Cam 810, in one embodiment, is rotated from position 802 toposition 804 so that a portion of cam 810 engages and exerts a force oncircuit card 408 b. The force slides circuit card 408 b into contactwith partition 412. Circuit card 408 b exerts a force on partition 412that slides partition 412 into contact with circuit card 408 a. In oneembodiment, partition 412 exerts a force on circuit card 408 a thatslides circuit card 408 a into contact with end wall 404. Thisrespectively closes gaps 420, 418, and 422 and clamps circuit card 408a, partition 412, circuit card 408 b, and end wall 404 in direct thermalcontact.

[0050] Cam 810, in one embodiment, is fabricated from metal, e.g., steelor aluminum, plastic, or the like. In another embodiment, serrations 812are distributed over the curved surface of cam 810, as shown in FIG. 10,which is the surface that bears against circuit card 108 b. In anotherembodiment, serrations 812 are rubber and are molded onto cam 410.Serrations 812 improve the contact resistance between cam 810 andcircuit card 408 b and facilitate the clamping of circuit card 408 a,partition 412, circuit card 408 b between cam 810 and end wall 404. Inone embodiment, cam 810 has aperture 814 passing through it forreceiving a shaft, such as shaft 817 shown in FIG. 9.

[0051]FIG. 9 is a side view of region 850 in FIG. 8 corresponding to oneembodiment of case 800. As seen in FIG. 9, cam 810 is rotatably attachedto end wall 406 using a bracket 816 and a shaft 817. Bracket 816includes protrusions 818 and 820, respectively having apertures 824 and826 passing therethrough. Cam 810 is rotatably attached to end wall 406by positioning cam 810 between protrusions 818 and 820 to align aperture814 of cam 810 with apertures 824 and 826 and passing shaft 817 throughapertures 824, 814, and 826. Cam 810 rotates about the longitudinal axisof shaft 817 and moves relative to protrusions 818 and 820 of bracket816.

[0052] Bracket 816, in one embodiment, is fabricated from metal, e.g.,steel or aluminum, plastic, or the like and is fixed to end wall 406 bywelding, gluing, bolting, or the like. In one embodiment, cam 810 issecured to shaft 817 using cap screws, set screws, an interference fit,or the like. Shaft 817, in one embodiment, is fabricated from metal,e.g., steel, aluminum, or the like, plastic, or the like. Shaft 817, inone embodiment, has a head 828 at one of its ends that is hexagonal, asshown in FIG. 8, square, slotted, Phillips, Allen, or the like. In oneembodiment, a nut 830 that is hexagonal or square is threaded onto shaft817 at end 832 of shaft 817. To rotate cam 810, a torque is applied tohead 828 using an appropriate wrench, screwdriver, or the like.

[0053]FIG. 11 is a side view of region 850 in FIG. 8 corresponding toanother embodiment of case 800. The embodiment of FIG. 11 includes twocams 1010 that are rotatably attached to end wall 406 in tandem using abracket 1016 for each cam 1010 and shaft 1017 that passes through therespective brackets 1016 and cams 1010. In other embodiments, bracket1016 and cams 1010 are as described above for bracket 816 and cam 810.Shaft 1017, in one embodiment, has a head 1028 at one of its ends thatis hexagonal, as shown in FIG. 11, square, slotted, Phillips, Allen, orthe like. In one embodiment, a nut 1030 that is hexagonal or square isthreaded onto shaft 1017 at end 1032. Cams 1010 are rotated intoengagement with circuit card 408 b by applying a torque to head 1028using an appropriate wrench, screwdriver, or the like.

[0054]FIG. 12 is an isometric view of region 850 in FIG. 8 correspondingto yet another embodiment of case 800. FIG. 13 is a side view of FIG.12, and FIG. 14 illustrates the embodiment of FIG. 12 in operation. Inthe embodiment of FIG. 12, end wall 1206 replaces end wall 406 andresilient elements 1202 and 1204 replace cam 810.

[0055] End wall 1206 includes recess 1208. In one embodiment, a bracket1210 and a nut 1212 are disposed within recess 1208 and are respectivelyfastened to wall 1206 using fasteners 1214 and 1216, as shown in FIGS.12 and 13. Bracket 1210 and nut 1212, in one embodiment, are fabricatedfrom metal, such as steel or aluminum, plastic, or the like. Fasteners1214 and 1216, in one embodiment, are screws or bolts. Alternatively,bracket 1210 and nut 1212, in other embodiments, are fastened to endwall 1206 by welding, gluing, or the like. In another embodiment,bracket 1210 and nut 1212 are fastened to a wall with no recess, such asend wall 406.

[0056] Bracket 1210 has an aperture 1218 passing through it, as shown inFIGS. 12 and 13. A sleeve 1220 passes through aperture 1218 and isslidable within aperture 1218. A shaft 1222 passes through sleeve 1220and is movable therein. An end 1224 of shaft 1222 is threaded into nut1212. Shaft 1222, in one embodiment, is fabricated from metal, e.g.,steel, aluminum, or the like, plastic, or the like. Shaft 1222, in oneembodiment, has a head 1226 at an end opposite end 1224 that ishexagonal, as shown in FIGS. 12 and 13, square, slotted, Phillips,Allen, or the like.

[0057] In one embodiment, shaft 1222 sequentially passes through awasher 1228, an aperture 1230 in resilient element 1202, a washer 1234,sleeve 1220, a washer 1236, an aperture 1238 in resilient element 1204,and a washer 1242 and threads into nut 1212, as shown in FIG. 13.Resilient element 1202 is sandwiched between washers 1228 and 1234, andresilient element 1204 is sandwiched between washers 1236 and 1242.Washers 1234 and 1236 respectively abut sleeve 1220 at ends 1244 and1246 of sleeve 1220, while washers 1228 and 1242 respectively abut head1226 of shaft 1222 and nut 1212. Shaft 1222 is movable within washer1228, aperture 1230 of resilient element 1202, washer 1234, washer 1236,aperture 1238 of resilient element 1204, and washer 1242.

[0058] Resilient elements 1202 and 1204, in one embodiment, areelastomers, e.g., polyvinyl, rubber, or the like. Washers 1228, 1234,1236, and 1242, in one embodiment, are metal, e.g., aluminum or steel,plastic, or the like and are circular, as shown in FIG. 12, square, etc.

[0059] In operation, a torque is applied to head 1226 of shaft 1222using an appropriate wrench, screwdriver, or the like to thread shaft1222 into nut 1212, causing shaft 1222 to move axially into nut 1212.This compresses resilient elements 1202 and 1204 axially between head1226 and nut 1212, causing resilient elements 1202 and 1204 to bulge ingenerally the radial direction, as shown in FIG. 14. As resilientelements 1202 and 1204 bulge radially, resilient elements 1202 and 1204engage circuit card 408 b to exert a force on circuit card 408 b, asshown in FIG. 14. This force closes gaps 420, 418, and 422 and clampscircuit card 408 a, partition 412, circuit card 408 b, and end wall 404in direct thermal contact, as described above.

[0060] More specifically, when a torque is applied to head 1226 of shaft1222, head 1226 exerts an axial force on washer 1228, which in turnexerts an axial force on resilient element 1202. A portion of the axialforce exerted on resilient element 1202 compresses resilient element1202 axially, causing resilient element 1202 to bulge in generally theradial direction, as shown in FIG. 14. Another portion of the axialforce exerted on resilient element 1202 is transmitted to washer 1234,which in turn exerts an axial force on end 1244 of sleeve 1220. Theaxial force exerted on sleeve 1220 slides sleeve 1220 relative tobracket 1210 within aperture 1218 of bracket 1210. This causes end 1246to exert an axial force on washer 1236, which in turn exerts an axialforce on resilient element 1204. The axial force exerted on resilientelement 1204 compresses resilient element 1204 axially between washer1236 and washer 1242, causing resilient element 1204 to bulge ingenerally the radial direction, as shown in FIG. 14.

[0061]FIG. 15 illustrates case 1500, another embodiment of the presentinvention. Elements that are common to FIGS. 15 and 7 are numbered as inFIG. 7 and are as described above. Cam 1510 is rotated from a position1520 to a position 1530, as shown in FIG. 15, so that a portion of cam1510 engages circuit card 706 to exert a force on circuit card 706. Theforce, in one embodiment, slides circuit card 706 into direct contactwith end wall 704, thereby closing gap 714 to clamp circuit card 706 andend wall 704 in direct thermal contact.

[0062] In one embodiment, region 1550 of FIG. 15 is as described forregion 850 of FIG. 8 above for the embodiment of case 800 shown in FIGS.9 and 10, and cam 1510 is as described for cam 810. In anotherembodiment, region 1550 of FIG. 15 is as described for region 850 ofFIG. 8 above for the embodiment of case 800 shown in FIG. 11, and a pairof cams in tandem engages circuit card 706 to exert a force on circuitcard 706. In yet another embodiment, region 1550 of FIG. 15 is asdescribed for region 850 of FIG. 8 above for the embodiment of case 800shown in FIGS. 1214, and a pair of resilient elements engages circuitcard 706 to exert a force on circuit card 706.

[0063]FIG. 16 illustrates receptacle 1600, another embodiment of thepresent invention. Receptacle 1600 includes sidewalls 1602 and 1604 andend walls 1606 and 1607 that are fabricated from materials havingsuitable thermal and structural properties, such as aluminum, copper,brass, bronze, or the like.

[0064] Receptacle 1600 includes a frame 1608 divided into sub-frames1608 ₁ and 1608 ₂ by partition 1610. Sub-frame 1608 ₂ and partition1610, in one embodiment, are in slidable contact with sidewalls 1602 and1604. Sub-frames 1608 ₁ and 1608 ₂ are respectively partitioned into anarray of slots having slots 1620 ₁ toy 1620 _(N) by partitions 1612 ₁ to1612 _(N) that are perpendicular to partition 1610, as shown in FIG. 16.Each slot of slots 1620 ₁ to 1620 _(N) respectively confines one ofcircuit cards 1622 ₁ to 1622 _(N) to a particular location within case1600. Frame 1608 is fabricated from materials having suitable thermaland structural properties, such as aluminum, copper, brass, bronze, orthe like. Circuit cards 1622 ₁ to 1622 _(N), in one embodiment, are asdescribed above for circuit card 106 108 a, or 108 b.

[0065] A gap 1624 separates frame 1608 from end wall 1606. Cams 1611 aredisposed within gap 1624. Cams 1611 are rotated into and out ofengagement with frame 1608. When cams 1611 engage frame 1608, cams 1611respectively exert a force on frame 1608, and, in particular, sub-frame1608 ₂.

[0066] In one embodiment, regions 1650 of FIG. 16 are as described forregion 850 of FIG. 8 above for the embodiment of case 800 shown in FIGS.9 and 10, and cams 1611 are as described for cam 810. In anotherembodiment, regions 1650 of FIG. 16 are as described for region 850 ofFIG. 8 above for the embodiment of case 800 shown in FIG. 11, and twotandem pairs of cams engage frame 1608 to exert a force on frame 1608.In yet another embodiment, regions 1650 of FIG. 16 are as described forregion 850 of FIG. 8 above for the embodiment of case 800 shown in FIGS.12-14, and two pairs of resilient elements engage frame 1608 to exert aforce on frame 1608. In other embodiments, a single region 1650 midwaybetween sidewalls 1602 and 1604 replaces regions 1650, and a single cam,a tandem pair of cams, or a pair of resilient elements are locatedmidway between sidewalls 1602 and 1604.

[0067]FIG. 17 is an enlarged view of region 1675 of FIG. 16 andcorresponds to when a force, as represented by arrow 1750, is initiallyexerted on sub-frame 1608 ₂, for example, by cam 1611. FIG. 17 shows, inone embodiment, that the circuit cards 1622 ₁ to 1622 _(N), e.g.,circuit cards 1622 ₁ and 1622 _(N), extend beyond sub-frames 1608 ₁ and1608 ₂ and partitions 1612 ₁ to 1612 _(N), e.g., 1612 ₁ and 1612 _(N),by a distance 1702. In other embodiments, the distance 1702 issubstantially zero, and circuit cards 1622 ₁ to 1622 _(N) aresubstantially flush with sub-frames 1608 ₁ and 1608 ₂ and partitions1612 ₁ to 1612 _(N). Moreover, circuit cards 1622 ₁ to 1622 _(N), e.g.,circuit cards 1622 ₁ and 1622 _(N), are each separated from partition1610 by a gap 1704.

[0068] When a force, as indicted by arrow 1750, is exerted on frame 1608at sub-frame 1608 ₂, the force slides sub-frame 1608 ₂ so that thecircuit cards of circuit cards 1622 ₁ to 1622 _(N) that are in sub-frame1608 ₂ contact partition 1610 and exert a force on partition 1610. Theforce exerted on partition 1610 slides partition 1610 into contact withthe circuit cards of circuit cards 1622 ₁ to 1622 _(N) that are insub-frame 1608 ₁. In this way, the circuit cards of circuit cards 1622 ₁to 1622 _(N) contained in the slots of sub-frame 1608 ₂ are clampedbetween sub-frame 1608 ₂ and partition 1610, and the circuit cards ofcircuit cards 1622 ₁ to 1622 _(N) contained in the slots of sub-frame1608 ₁ are clamped between and partition 1610 and sub-frame 1608 ₁.Therefore, circuit cards 1622 ₁ to 1622 _(N) are clamped in directcontact with frame 1608, which is in contact with end walls 1606 and1607 and sidewalls 1602 and 1604 of case 1600. This substantiallyincreases the heat transfer from circuit cards 1622 ₁ to 1622 _(N) tocase 1600 relative to situations where circuit cards 1622 ₁ to 1622 _(N)are not clamped in direct contact with frame 1608.

[0069]FIG. 18 illustrates receptacle 1800, another embodiment of thepresent invention. Receptacle 1800 includes sidewalls 1802 and 1804 andend walls 1806 and 1807 that are fabricated from materials havingsuitable thermal and structural properties, such as aluminum, copper,brass, bronze, or the like.

[0070] Receptacle 1800 includes frames 1808 and 1809, respectivelydivided into sub-frames 1808 ₁ and 1808 ₂ by partition 1810 andsub-frames 1809 ₁ and 1809 ₂ by partition 1811. Sub-frames 1808 ₂ and1809 ₂ and partitions 1810 and 1811, in one embodiment, are in slidablecontact with sidewalls 1802 and 1804. Sub-frames 1808 ₁ and 1808 ₂ arepartitioned into an array of slots having slots 1820 ₁ to 1820 _(N) bypartitions 1812 ₁ to 1812 _(N) that are perpendicular to partition 1810,as shown in FIG. 18. Sub-frames 1809 ₁ and 1809 ₂ are partitioned intoan array of slots having slots 1821 ₁ to 1821 _(N) by partitions 1813 ₁to 1813 _(N) that are perpendicular to partition 1811, as shown in FIG.18. Each slot of slots 1820 ₁ to 1820 _(N) respectively confines one ofcircuit cards 1822 ₁ to 1822 _(N) to a particular location within frame1808. Each slot of slots 1821 ₁ to 1821 _(N) respectively confines oneof circuit cards 1823 ₁ to 1823 _(N) to a particular location withinframe 1809.

[0071] Frames 1808 and 1809 are fabricated from materials havingsuitable thermal and structural properties, such as aluminum, copper,brass, bronze, or the like. Circuit cards 1822 ₁ to 1822 _(N) andcircuit cards 1823 ₁ to 1823 _(N) in one embodiment, are as describedabove for circuit card 106, 108 a, or 108 b.

[0072] Frames 1808 and 1809 are separated by a gap 1824 that containscams 1825. Each cam 1825 is rotatably attached to frame 1808, and, inparticular, to sub-frame 1808 ₂ of frame 1808. Cams 1825 are rotatedinto and out of engagement with frame 1809, and, in particular, into andout of engagement with sub-frame 1809 ₂ of frame 1809. When cams 1825engage sub-frame 1809 ₂, cams 1825 respectively exert a force onsub-frame 1809 ₂ producing a reaction force that is exerted on sub-frame1808 ₂. In this way, when each cam 1825 is rotated into engagement withframe 1809, a force is exerted on both frames 1809 and 1808, and, inparticular, on both sub-frames 1809 ₂ and 1808 ₂.

[0073] In one embodiment, the regions 1830 and 1840 are as described forregion 1675 in FIG. 16. When a force is exerted on both sub-frames 1809₂ and 1808 ₂, e.g., by each of cams 1825, the force slides sub-frame1808 ₂ so that the circuit cards of circuit cards 1822 ₁ to 1822 _(N)that are in sub-frame 1808 ₂ contact partition 1810 and exert a force onpartition 1810. The force exerted on partition 1810 slides partition1810 into contact with the circuit cards of circuit cards 1822 ₁ to 1822_(N) that are in sub-frame 1808 ₁. In this way, the circuit cards ofcircuit cards 1822 ₁ to 1822 _(N) contained in the slots of sub-frame1808 ₂ are clamped between sub-frame 1808 ₂ and partition 1810, and thecircuit cards of circuit cards 1822 ₁ to 1822 _(N) contained in theslots of sub-frame 1808 ₁ are clamped between and partition 1810 andsub-frame 1808 ₁.

[0074] The force also slides sub-frame 1809 ₂ SO that the circuit cardsof circuit cards 1823 ₁ to 1823 _(N) that are in sub-frame 1809 ₂contact partition 1811 and exert a force on partition 1811. The forceexerted on partition 1811 slides partition 1811 into contact with thecircuit cards of circuit cards 1823 ₁ to 1823 _(N) that are in sub-frame1809 ₁. In this way, the circuit cards of circuit cards 1823 ₁ to 1823_(N) contained in the slots of sub-frame 1809 ₂ are clamped betweensub-frame 1809 ₂ and partition 1811, and the circuit cards of circuitcards 1823 ₁ to 1823 _(N) contained in the slots of sub-frame 1809 ₁ areclamped between and partition 1811 and sub-frame 1809 ₁.

[0075] In one embodiment, regions 1850 of FIG. 18 are as described forregion 850 of FIG. 8 above for the embodiment of case 800 shown in FIGS.9 and 10, and cams 1825 are as described for cam 810. In anotherembodiment, regions 1850 of FIG. 18 are as described for region 850 ofFIG. 8 above for the embodiment of case 800 shown in FIG. 11, and twotandem pairs of cams are attached to frame 1808 and are rotated toengage frame 1809 to exert a force on both frames 1808 and 1809. In yetanother embodiment, regions 1850 of FIG. 18 are as described for region850 of FIG. 8 above for the embodiment of case 800 shown in FIGS. 12-14,and two pairs of resilient elements are attached to frame 1808 andengage frame 1809 to exert a force on both frames 1808 and 1809. Inother embodiments, a single region 1850 midway between sidewalls 1802and 1804 replaces regions 1850, and a single cam, a tandem pair of cams,or a pair of resilient elements are located midway between sidewalls1802 and 1804.

[0076] In one embodiment, region 1875 of FIG. 18 is as shown in theexploded view of FIG. 19. In this embodiment, sub-frame portions 1908 ₂and 1909 ₂ respectively replace the portions of sub-frames 1808 ₂ and1809 ₂ contained within region 1875, and gap 1924 replaces gap 1824.Sub-frame portions 1908 ₂ and 1909 ₂ respectively have recesses 1910 and1911, with the recess 1910 having resilient elements 1902 and 1904disposed therein. In one embodiment, resilient elements 1902 and 1904are as described above in conjunction with FIGS. 12-14.

[0077] Resilient elements 1902 and 1904 are compressed axially betweenhead 1918 of shaft 1920 and nut 1922 when a torque is applied to head1918 to thread shaft 1920 axially into nut 1922. This causes resilientelements 1902 and 1904 to bulge in generally the radial direction. Asresilient elements 1902 and 1904 bulge generally radially, resilientelements 1902 and 1904 engage sub-frame portion 1909 ₂ within recess1911. When resilient elements 1902 and 1904 engage sub-frame portion1909 ₂, resilient elements 1902 and 1904 respectively exert a force onsub-frame portion 1909 ₂ producing a reaction force that is exerted onsub-frame portion 1908 ₂. In this way, a force is exerted on bothsub-frame portions 1908 ₂ and 1909 ₂.

[0078] In one embodiment, a pair of cases 1800 is located within ahousing, such as housing 2000 shown in FIG. 20. Housing 2000 has twocompartments 2002 that are closed by covers 2004. Each of compartments2002 receives a case 1800, as shown in FIG. 20, which, in oneembodiment, is thermally coupled to housing 2000, as described in U.S.patent application Ser. No. 09/804,129, entitled MECHANICAL HOUSING,which application is incorporated herein by reference.

Conclusion

[0079] Embodiments of the present invention have been described. Theembodiments provide cases that clamp circuit cards within them toimprove the thermal contact between the circuit cards and the cases,thereby reducing the risk of thermal failure.

[0080] Although specific embodiments have been illustrated and describedin this specification, it will be appreciated by those of ordinary skillin the art that any arrangement that is calculated to achieve the samepurpose may be substituted for the specific embodiment shown. Thisapplication is intended to cover any adaptations or variations of thepresent invention. For example, although cam 810 is portrayed in theaccompanying figures as being oval, cam 810 can also be circular,elliptical, or any suitable shape. Moreover, serrations 412, as shown inFIG. 10, can be eliminated from the curved surface of cam 810, orserrations 412 can be of a material other than rubber, such as plastic,metal, or the like. Although resilient elements 1202 and 1204 are shownto be hollow cylinders in FIG. 13, resilient elements 1202 and 1204 canhave other geometries, such as cubes having apertures passing throughthem. Further, although cams 1611 are rotatably attached to end wall1606, as shown in FIG. 16, and are rotatable into engagement with frame1608, cams 1611 can be rotatably attached to frame 1608 and can berotated into engagement with end wall 1606. Although cams 1825 arerotatably attached to frame 1808, as shown in FIG. 18, and are rotatableinto engagement with frame 1809, cams 1825 can be rotatably attached toframe 1809 and can be rotatable into engagement with frame 1808.

What is claimed is:
 1. A receptacle for confining circuit cards todifferent locations within a housing, the receptacle comprising: a framecomprising an array of slots, each slot containing one of the circuitcards; and a cam selectively engageable with the frame for clamping thecircuit cards within the frame.
 2. The receptacle of claim 1, whereinthe frame is partitioned into first and second sub-frames by a firstpartition and each of the first and second sub-frames partitioned intoan array of slots by a plurality of second partitions.
 3. The receptacleof claim 2, wherein the first sub-frame is movable relative to thesecond sub-frame and is in slidable contact with the receptacle.
 4. Thereceptacle of claim 3, wherein the first partition is in slidablecontact with the receptacle.
 5. The receptacle of claim 4, wherein thecam is engageable with the first sub-frame for sliding the firstsub-frame so that circuit cards that are in the first sub-frame contactthe first partition and sliding the first partition into contact withthe circuit cards of the second sub-frame to clamp the circuit cardscontained in the slots of the first sub-frame between the firstsub-frame and the first partition and the circuit cards contained in theslots of the second sub-frame between the first partition and the secondsub-frame.
 6. The receptacle of claim 1, wherein the cam is selectedfrom the group consisting of a pair of cams in tandem, a pair of cams,and two tandem pairs of cams.
 7. The receptacle of claim 1, wherein thecam is disposed within the receptacle.
 8. The receptacle of claim 1,wherein the cam is rotatably attached to the receptacle.
 9. Thereceptacle of claim 1, wherein the cam is disposed on a shaft thatrotates the cam into and out of engagement with the frame.
 10. Thereceptacle of claim 1, wherein the cam comprises a curved surfacecomprising serrations.
 11. The receptacle of claim 1, wherein the framecomprises a pair of frames, the cam attached to one of the pair offrames and selectively engageable with the other of the pair of framesfor clamping the circuit cards within each of the pair of frames.
 12. Areceptacle for confining circuit cards to different locations within ahousing, the receptacle comprising: at least one frame partitioned intofirst and second sub-frames by a first partition, each of the first andsecond sub-frames partitioned into an array of slots by a plurality ofsecond partitions, each slot containing one of the circuit cards; and atleast one cam selectively engageable with the first sub-frame to clampthe circuit cards within the at least one frame.
 13. The receptacle ofclaim 12, wherein the at least one cam is selected from the groupconsisting of a pair of cams in tandem, a pair of cams, and two tandempairs of cams.
 14. The receptacle of claim 12, wherein the at least onecam is disposed within the receptacle.
 15. The receptacle of claim 12,wherein the at least one cam is rotatably attached to the receptacle.16. The receptacle of claim 12, wherein the at least one cam is disposedon a shaft that rotates the at least one cam into and out of engagementwith the first sub-frame.
 17. The receptacle of claim 12, wherein the atleast one cam comprises a curved surface comprising serrations.
 18. Thereceptacle of claim 12, wherein the first sub-frame is movable relativeto the second sub-frame and is in slidable contact with the receptacle.19. The receptacle of claim 18, wherein the first partition is inslidable contact with the receptacle.
 20. The receptacle of claim 19,wherein the at least one cam is engageable with the first sub-frame forsliding the first sub-frame so that circuit cards that are in the firstsub-frame contact the first partition and sliding the first partitioninto contact with the circuit cards of the second sub-frame to clamp thecircuit cards contained in the slots of the first sub-frame between thefirst sub-frame and the first partition and the circuit cards containedin the slots of the second sub-frame between the first partition and thesecond sub-frame.
 21. A receptacle for confining circuit cards todifferent locations within a housing, the receptacle comprising: atleast one frame partitioned into first and second sub-frames by a firstpartition, each of the first and second sub-frames partitioned into anarray of slots by a plurality of second partitions, each slot containingone of the circuit cards; wherein the first sub-frame is movablerelative to the second sub-frame and is in slidable contact with thereceptacle; wherein the first partition is in slidable contact with thereceptacle; and at least one cam disposed within the receptacle androtatably attached to the receptacle, the at least one cam selectivelyrotatable for selectively engaging the first sub-frame for sliding thefirst sub-frame so that circuit cards of the first sub-frame contact thefirst partition and sliding the first partition into contact with thecircuit cards of the second sub-frame to clamp the circuit cardscontained in the slots of the first sub-frame between the firstsub-frame and the first partition and the circuit cards contained in theslots of the second sub-frame between the first partition and the secondsub-frame.
 22. The receptacle of claim 21, wherein the at least one camis selected from the group consisting of a pair of cams in tandem, apair of cams, and two tandem pairs of cams.
 23. The receptacle of claim21, wherein the at least one cam is disposed on a shaft that rotates theat least one cam into and out of engagement with the first sub-frame.24. A receptacle for confining circuit cards to different locationswithin a housing, the receptacle comprising: first and second frames,each of the first and second frames partitioned into first and secondsub-frames by a first partition, each of the first and second sub-framespartitioned into an array of slots by a plurality of second partitions,each slot containing one of the circuit cards; and at least one camdisposed between the first and second frames, the at least one camrotatably attached to the first frame and adapted to engage the secondframe to exert a force on each of the first and second frames forclamping the circuit cards within the first and second frames.
 25. Thereceptacle of claim 24, wherein the at least one cam is selected fromthe group consisting of a pair of cams in tandem, a pair of cams, andtwo tandem pairs of cams.
 26. The receptacle of claim 24, wherein the atleast one cam is disposed on a shaft that is rotatably attached to thefirst frame, the shaft rotating the at least one cam into and out ofengagement with the second frame.
 27. The receptacle of claim 24,wherein the at least one cam comprises a curved surface comprisingserrations.
 28. The receptacle of claim 24, wherein the first sub-frameof each of the first and second frames is movable relative to the secondsub-frame of each of the first and second frames and is in slidablecontact with the receptacle.
 29. The receptacle of claim 28, wherein thefirst partition of each of the first and second frames is in slidablecontact with the receptacle.
 30. The receptacle of claim 29, wherein theforce exerted on the first and second frames slides the first sub-frameof each of the first and second frames so that circuit cards of thefirst sub-frame of each of the first and second frames contact the firstpartition of each of the first and second frames and slides the firstpartition of each of the first and second frames into contact with thecircuit cards of the second sub-frame of each of the first and secondframes to clamp the circuit cards contained in the slots of the firstsub-frame of each of the first and second frames between the firstsub-frame and the first partition of each of the first and second framesand the circuit cards contained in the slots of the second sub-frame ofeach of the first and second frames between the first partition and thesecond sub-frame of each of the first and second frames.
 31. Thereceptacle of claim 24, wherein the receptacle is thermally coupled tothe housing.
 32. A receptacle for confining circuit cards to differentlocations within a housing, the receptacle comprising: first and secondframes, each of the first and second frames partitioned into first andsecond sub-frames by a first partition, each of the first and secondsub-frames partitioned into an array of slots by a plurality of secondpartitions, each slot containing one of the circuit cards; wherein thefirst sub-frame of each of the first and second frames is movablerelative to the second sub-frame of each of the first and second framesand is in slidable contact with the receptacle; wherein the firstpartition of each of the first and second frames is in slidable contactwith the receptacle; and at least one cam disposed between the first andsecond frames, the at least one cam rotatably attached to the firstsub-frame of the first frame and is selectively rotatable for toengaging the first sub-frame of the second frame to exert a force on thefirst sub-frame of each of the first and second frames to slide thefirst sub-frame of each of the first and second frames so that circuitcards of the first sub-frame of each of the first and second framescontact the first partition of each of the first and second frames andto slide the first partition of each of the first and second frames intocontact with the circuit cards of the second sub-frame of each of thefirst and second frames to clamp the circuit cards contained in theslots of the first sub-frame of each of the first and second framesbetween the first sub-frame and the first partition of each of the firstand second frames and the circuit cards contained in the slots of thesecond sub-frame of each of the first and second frames between thefirst partition and the second sub-frame of each of the first and secondframes.
 33. The receptacle of claim 32, wherein the at least one cam isselected from the group consisting of a pair of cams in tandem, a pairof cams, and two tandem pairs of cams.
 34. The receptacle of claim 32,wherein the at least one cam is disposed on a shaft that is rotatablyattached to the first sub-frame of the first frame, the shaft rotatingthe at least one cam into and out of engagement with the first sub-frameof the second frame.
 35. The receptacle of claim 32, wherein thereceptacle is thermally coupled to the housing.
 36. A receptacle forconfining circuit cards to different locations within a housing, thereceptacle comprising: a frame comprising an array of slots, each slotcontaining one of the circuit cards; a shaft rotatably attached to thereceptacle, the shaft having a head at one end and a nut at an end ofthe shaft opposite the head; and at least one resilient element disposedon the shaft between the head and the nut, the at least one resilientelement axially compressible between the head and nut to bulge generallyperpendicularly to the axial direction into engagement with the firstframe for clamping the circuit cards within the frame.
 37. Thereceptacle of claim 36, wherein the frame is partitioned into first andsecond sub-frames by a first partition and each of the first and secondsub-frames partitioned into an array of slots by a plurality of secondpartitions.
 38. The receptacle of claim 37, wherein the first sub-frameis movable relative to the second sub-frame and is in slidable contactwith the receptacle.
 39. The receptacle of claim 38, wherein the firstpartition is in slidable contact with the receptacle.
 40. The receptacleof claim 36, wherein the at least one resilient element bulges generallyperpendicularly to the axial direction into engagement with the firstsub-frame for sliding the first sub-frame so that circuit cards that arein the first sub-frame contact the first partition and sliding the firstpartition into contact with the circuit cards of the second sub-frame toclamp the circuit cards contained in the slots of the first sub-framebetween the first sub-frame and the first partition and the circuitcards contained in the slots of the second sub-frame between the firstpartition and the second sub-frame.
 41. The receptacle of claim 36,wherein the frame comprises a pair of frames, the shaft rotatablyattached to one of the pair of frames and the at least one resilientelement bulges generally perpendicularly to the axial direction intoengagement with the other of the pair of frames for clamping the circuitcards within each of the pair of frames.
 42. The receptacle of claim 36,wherein the at least one resilient element is a pair of resilientelements.
 43. The receptacle of claim 42, and further comprising asleeve disposed within a bracket attached to the receptacle, the sleevein slidable contact with the bracket, the shaft passing through thesleeve such that the shaft is rotatable within the sleeve, the sleevelocated between the respective resilient elements of the pair ofresilient elements.
 44. The receptacle of claim 36, wherein the shaft isin threaded engagement with the nut.
 45. The receptacle of claim 36,wherein the nut is attached to the receptacle.
 46. The receptacle ofclaim 44, wherein the shaft threads into the nut to axially compress theat least one resilient element.
 47. A receptacle for confining circuitcards to different locations within a housing, the receptaclecomprising: at least one frame partitioned into first and secondsub-frames by a first partition, each of the first and second sub-framespartitioned into an array of slots by a plurality of second partitions,each slot containing one of the circuit cards; a shaft rotatablyattached to the receptacle, the shaft having a head at one end and a nutat an end of the shaft opposite the head; and at least one resilientelement disposed on the shaft between the head and the nut, the at leastone resilient element axially compressible between the head and nut tobulge generally perpendicularly to the axial direction into engagementwith the first sub-frame for clamping the circuit cards within the atleast one frame.
 48. The receptacle of claim 47, wherein the at leastone resilient element is a pair of resilient elements.
 49. Thereceptacle of claim 48, and further comprising a sleeve disposed withina bracket attached to the receptacle, the sleeve in slidable contactwith the bracket, the shaft passing through the sleeve such that theshaft is rotatable within the sleeve, the sleeve located between therespective resilient elements of the pair of resilient elements.
 50. Thereceptacle of claim 47, wherein the shaft is in threaded engagement withthe nut.
 51. The receptacle of claim 47, wherein the nut is attached tothe receptacle.
 52. The receptacle of claim 50, wherein the shaftthreads into the nut to axially compress the at least one resilientelement.
 53. The receptacle of claim 47, wherein the first sub-frame ismovable relative to the second sub-frame and is in slidable contact withthe receptacle.
 54. The receptacle of claim 53, wherein the firstpartition is in slidable contact with the receptacle.
 55. The receptacleof claim 54, wherein the at least one resilient element bulges generallyperpendicularly to the axial direction into engagement with the firstsub-frame for sliding the first sub-frame so that circuit cards of thefirst sub-frame contact the first partition and sliding the firstpartition into contact with the circuit cards of the second sub-frame toclamp the circuit cards contained in the slots of the first sub-framebetween the first sub-frame and the first partition and the circuitcards contained in the slots of the second sub-frame between the firstpartition and the second sub-frame.
 56. A receptacle for confiningcircuit cards to different locations within a housing, the receptaclecomprising: at least one frame partitioned into first and secondsub-frames by a first partition, each of the first and second sub-framespartitioned into an array of slots by a plurality of second partitions,each slot containing one of the circuit cards; a shaft having a head atone end; a nut attached to the receptacle and in threaded engagementwith the shaft adjacent an end of the shaft opposite the head; a sleevedisposed within a bracket attached to the receptacle, the sleeve inslidable contact with the bracket, the shaft passing through the sleevesuch that the shaft is rotatable within the sleeve; and first and secondresilient elements disposed on the shaft respectively on either side ofthe sleeve and between the head and the nut; the first resilient elementaxially compressible between the head and the sleeve and the secondresilient element axially compressible between the sleeve and the nut torespectively bulge generally perpendicularly to the axial direction intoengagement with the first sub-frame for clamping the circuit cardswithin the at least one frame.
 57. The receptacle of claim 56, whereinthe shaft threads into the nut to axially compress the first resilientelement between the head and the sleeve and the second resilient elementbetween the sleeve and the nut.
 58. The receptacle of claim 56, whereinthe first sub-frame is movable relative to the second sub-frame and isin slidable contact with the receptacle.
 59. The receptacle of claim 58,wherein the first partition is in slidable contact with the receptacle.60. The receptacle of claim 59, wherein each of the first and secondresilient elements bulges generally perpendicularly to the axialdirection into engagement with the first sub-frame for sliding the firstsub-frame so that circuit cards of the first sub-frame contact the firstpartition and sliding the first partition into contact with the circuitcards of the second sub-frame to clamp the circuit cards contained inthe slots of the first sub-frame between the first sub-frame and thefirst partition and the circuit cards contained in the slots of thesecond sub-frame between the first partition and the second sub-frame.61. A receptacle for confining circuit cards to different locationswithin a housing, the receptacle comprising: at least one framepartitioned into first and second sub-frames by a first partition, eachof the first and second sub-frames partitioned into an array of slots bya plurality of second partitions, each slot containing one of thecircuit cards; wherein the first sub-frame is movable relative to thesecond sub-frame and is in slidable contact with the receptacle; whereinthe first partition is in slidable contact with the receptacle; a shaftrotatably attached to the receptacle, the shaft having a head at one endand a nut at an end of the shaft opposite the head; and at least oneresilient element disposed on the shaft between the head and the nut,the at least one resilient element axially compressible between the headand nut to bulge generally perpendicularly to the axial direction forselectively engaging the first sub-frame for sliding the first sub-frameso that circuit cards of the first sub-frame contact the first partitionand sliding the first partition into contact with the circuit cards ofthe second sub-frame to clamp the circuit cards contained in the slotsof the first sub-frame between the first sub-frame and the firstpartition and the circuit cards contained in the slots of the secondsub-frame between the first partition and the second sub-frame.
 62. Thereceptacle of claim 61, wherein the at least one resilient element is apair of resilient elements.
 63. The receptacle of claim 62, and furthercomprising a sleeve disposed within a bracket attached to thereceptacle, the sleeve in slidable contact with the bracket, the shaftpassing through the sleeve such that the shaft is rotatable within thesleeve, the sleeve located between the respective resilient elements ofthe pair of resilient elements.
 64. The receptacle of claim 61, whereinthe shaft is in threaded engagement with the nut.
 65. The receptacle ofclaim 61, wherein the nut is attached to the receptacle.
 66. Thereceptacle of claim 64, wherein the shaft threads into the nut toaxially compress the at least one resilient element.
 67. A receptaclefor confining circuit cards to different locations within a housing, thereceptacle comprising: first and second frames, each of the first andsecond frames partitioned into first and second sub-frames by a firstpartition, each of the first and second sub-frames partitioned into anarray of slots by a plurality of second partitions, each slot containingone of the circuit cards; and a shaft disposed between the first andsecond frames and rotatably attached to the first frame, the shafthaving a head at one end and a nut at an end of the shaft opposite thehead; and at least one resilient element disposed on the shaft betweenthe head and the nut, the at least one resilient element axiallycompressible between the head and nut to bulge generally perpendicularlyto the axial direction into engagement with the first sub-frame of thesecond frame to exert a force on the first subframes of each of thefirst and second frames for clamping the circuit cards within the firstand second frames.
 68. The receptacle of claim 67, wherein the at leastone resilient element is a pair of resilient elements.
 69. Thereceptacle of claim 68, and further comprising a sleeve disposed withina bracket attached to the receptacle, the sleeve in slidable contactwith the bracket, the shaft passing through the sleeve such that theshaft is rotatable within the sleeve, the sleeve located between therespective resilient elements of the pair of resilient elements.
 70. Thereceptacle of claim 67, wherein the shaft is in threaded engagement withthe nut.
 71. The receptacle of claim 67, wherein the nut is attached tothe receptacle.
 72. The receptacle of claim 70, wherein the shaftthreads into the nut to axially compress the at least one resilientelement.
 73. The receptacle of claim 67, wherein the first sub-frame ofeach of the first and second frames is movable relative to the secondsub-frame of each of the first and second frames and is in slidablecontact with the receptacle.
 74. The receptacle of claim 73, wherein thefirst partition of each of the first and second frames is in slidablecontact with the receptacle.
 75. The receptacle of claim 74, wherein theforce exerted on the first subframes of each of the first and secondframes slides the first sub-frame of each of the first and second framesso that circuit cards of the first sub-frame of each of the first andsecond frames contact the first partition of each of the first andsecond frames and slides the first partition of each of the first andsecond frames into contact with the circuit cards of the secondsub-frame of each of the first and second frames to clamp the circuitcards contained in the slots of the first sub-frame of each of the firstand second frames between the first sub-frame and the first partition ofeach of the first and second frames and the circuit cards contained inthe slots of the second sub-frame of each of the first and second framesbetween the first partition and the second sub-frame of each of thefirst and second frames.
 76. The receptacle of claim 67, wherein thereceptacle is thermally coupled to the housing.
 77. A receptacle forconfining circuit cards to different locations within a housing, thereceptacle comprising: first and second frames, each of the first andsecond frames partitioned into first and second sub-frames by a firstpartition, each of the first and second sub-frames partitioned into anarray of slots by a plurality of second partitions, each slot containingone of the circuit cards; a shaft having a head at one end; a nutdisposed between the first and second frames, the nut attached to thefirst frame and in threaded engagement with the shaft adjacent an end ofthe shaft opposite the head; a sleeve disposed within a bracket, thebracket disposed between the first and second frames and attached to thefirst frame, the sleeve in slidable contact with the bracket, the shaftpassing through the sleeve such that the shaft is rotatable within thesleeve; and first and second resilient elements disposed on the shaftrespectively on either side of the sleeve and between the head and thenut; the first resilient element axially compressible between the headand the sleeve and the second resilient element axially compressiblebetween the sleeve and the nut to respectively bulge generallyperpendicularly to the axial direction into engagement with the firstsub-frame of the second frame to exert a force on the first sub-framesof each of the first and second frames for clamping the circuit cardswithin the first and second frames.
 78. The receptacle of claim 77,wherein the shaft threads into the nut to axially compress the firstresilient element between the head and the sleeve and the secondresilient element between the sleeve and the nut.
 79. The receptacle ofclaim 77, wherein the first sub-frame of each of the first and secondframes is movable relative to the second sub-frame of each of the firstand second frames and is in slidable contact with the receptacle. 80.The receptacle of claim 79, wherein the first partition of each of thefirst and second frames is in slidable contact with the receptacle. 81.The receptacle of claim 80, wherein the force exerted on the firstsub-frame of each of the first and second frames slides the firstsub-frame of each of the first and second frames so that circuit cardsof the first sub-frame of each of the first and second frames contactthe first partition of each of the first and second frames and slidesthe first partition of each of the first and second frames into contactwith the circuit cards of the second sub-frame of each of the first andsecond frames to clamp the circuit cards contained in the slots of thefirst sub-frame of each of the first and second frames between the firstsub-frame and the first partition of each of the first and second framesand the circuit cards contained in the slots of the second sub-frame ofeach of the first and second frames between the first partition and thesecond sub-frame of each of the first and second frames.
 82. Thereceptacle of claim 77, wherein the receptacle is thermally coupled tothe housing.
 83. A receptacle for confining circuit cards to differentlocations within a housing, the receptacle comprising: first and secondframes, each of the first and second frames partitioned into first andsecond sub-frames by a first partition, each of the first and secondsub-frames partitioned into an array of slots by a plurality of secondpartitions, each slot containing one of the circuit cards; wherein thefirst sub-frame of each of the first and second frames is movablerelative to the second sub-frame of each of the first and second framesand is in slidable contact with the receptacle; wherein the firstpartition of each of the first and second frames is in slidable contactwith the receptacle; a shaft disposed between the first and secondframes and rotatably attached to the first frame, the shaft having ahead at one end and a nut at an end of the shaft opposite the head; andat least one resilient element disposed on the shaft between the headand the nut, the at least one resilient element axially compressiblebetween the head and nut to bulge generally perpendicularly to the axialdirection to engage the first sub-frame of the second frame to exert aforce on the first sub-frame of each of the first and second frames toslide the first sub-frame of each of the first and second frames so thatcircuit cards of the first sub-frame of each of the first and secondframes contact the first partition of each of the first and secondframes and to slide the first partition of each of the first and secondframes into contact with the circuit cards of the second sub-frame ofeach of the first and second frames to clamp the circuit cards containedin the slots of the first sub-frame of each of the first and secondframes between the first sub-frame and the first partition of each ofthe first and second frames and the circuit cards contained in the slotsof the second sub-frame of each of the first and second frames betweenthe first partition and the second sub-frame of each of the first andsecond frames.
 84. The receptacle of claim 83, wherein the at least oneresilient element is a pair of resilient elements.
 85. The receptacle ofclaim 84, and further comprising a sleeve disposed within a bracketattached to the receptacle, the sleeve in slidable contact with thebracket, the shaft passing through the sleeve such that the shaft isrotatable within the sleeve, the sleeve located between the respectiveresilient elements of the pair of resilient elements.
 86. The receptacleof claim 83, wherein the shaft is in threaded engagement with the nut.87. The receptacle of claim 83, wherein the nut is attached to thereceptacle.
 88. The receptacle of claim 86, wherein the shaft threadsinto the nut to axially compress the at least one resilient element. 89.The receptacle of claim 83, wherein the receptacle is thermally coupledto the housing.
 90. A receptacle for confining circuit cards todifferent locations within a housing, the receptacle comprising: firstand second frames, each of the first and second frames partitioned intofirst and second sub-frames by a first partition, each of the first andsecond sub-frames partitioned into an array of slots by a plurality ofsecond partitions, each slot containing one of the circuit cards;wherein the first sub-frame of each of the first and second frames ismovable relative to the second sub-frame of each of the first and secondframes and is in slidable contact with the receptacle; wherein the firstpartition of each of the first and second frames is in slidable contactwith the receptacle; a shaft having a head at one end; a nut disposedbetween the first and second frames, the nut attached to the first frameand in threaded engagement with the shaft adjacent an end of the shaftopposite the head; a sleeve disposed within a bracket, the bracketdisposed between the first and second frames and attached to the firstframe, the sleeve in slidable contact with the bracket, the shaftpassing through the sleeve such that the shaft is rotatable within thesleeve; and first and second resilient elements disposed on the shaftrespectively on either side of the sleeve and between the head and thenut; the first resilient element axially compressible between the headand the sleeve and the second resilient element axially compressiblebetween the sleeve and the nut to respectively bulge generallyperpendicularly to the axial direction into engagement with the firstsub-frame of the second frame to exert a force on the first sub-frame ofeach of the first and second frames to slide the first sub-frame of eachof the first and second frames so that circuit cards of the firstsub-frame of each of the first and second frames contact the firstpartition of each of the first and second frames and to slide the firstpartition of each of the first and second frames into contact with thecircuit cards of the second sub-frame of each of the first and secondframes to clamp the circuit cards contained in the slots of the firstsub-frame of each of the first and second frames between the firstsub-frame and the first partition of each of the first and second framesand the circuit cards contained in the slots of the second sub-frame ofeach of the first and second frames between the first partition and thesecond sub-frame of each of the first and second frames.
 91. Thereceptacle of claim 90, wherein the shaft threads into the nut toaxially compress the first resilient element between the head and thesleeve and the second resilient element between the sleeve and the nut.92. The receptacle of claim 90, wherein the receptacle is thermallycoupled to the housing.
 93. A method for clamping a plurality of circuitcards within a receptacle, the method comprising: attaching at least onecam rotatably to the receptacle; rotating selectively the at least onecam to engage a frame within the receptacle, the frame partitioned intofirst and second sub-frames by a first partition, each of the first andsecond sub-frames partitioned into an array of slots by a plurality ofsecond partitions, each slot containing one of the circuit cards;exerting a force on the first sub-frame using the at least one cam;sliding the first sub-frame using the force exerted on the firstsub-frame so that circuit cards of the first sub-frame contact the firstpartition; exerting a force on the first partition using the circuitcards of the first sub-frame; sliding the first partition into contactwith the circuit cards of the second sub-frame using the force exertedon the first partition by the circuit cards of the first sub-frame; andsecuring the circuit cards contained in the slots of the first sub-framebetween the first sub-frame and the first partition and the circuitcards contained in the slots of the second sub-frame between the firstpartition and the second sub-frame by maintaining the force on the firstsub-frame using the at least one cam.
 94. The method of claim 93,wherein attaching the at least one cam rotatably includes selecting theat least one cam from the group consisting of a pair of cams, a tandempair of cams, and two tandem pairs of cams.
 95. A method for clamping aplurality of circuit cards within a receptacle having first and secondframes, each frame partitioned into first and second sub-frames by afirst partition, each of the first and second sub-frames partitionedinto an array of slots by a plurality of second partitions, each slotcontaining one of the circuit cards, the method comprising: disposing atleast one cam between the first and second frames; attaching the atleast one cam rotatably to the first sub-frame of the first frame;rotating selectively the at least one cam to engage the first sub-frameof the second frame; exerting a force on the first sub-frame of each ofthe first and second frames using the at least one cam; sliding thefirst sub-frame of each of the first and second frames using the forceexerted on the first sub-frame of each of the first and second frames sothat circuit cards of the first sub-frame of each of the first andsecond frames contact the first partition of each of the first andsecond frames; exerting a force on the first partition of each of thefirst and second frames using the circuit cards of the first sub-frameof each of the first and second frames; sliding the first partition ofeach of the first and second frames into contact with the circuit cardsof the second sub-frame of each of the first and second frames using theforce exerted on the first partition of each of the first and secondframes by the circuit cards of the first sub-frame of each of the firstand second frames; and securing the circuit cards contained in the slotsof the first sub-frame of each of the first and second frames betweenthe first sub-frame and the first partition of each of the first andsecond frames and the circuit cards contained in the slots of the secondsub-frame of each of the first and second frames between the firstpartition and the second sub-frame of each of the first and secondframes by maintaining the force on the first sub-frame of each of thefirst and second frames using the at least one cam.
 96. The method ofclaim 95, wherein attaching the at least one cam rotatably includesselecting the at least one cam from the group consisting of a pair ofcams, a tandem pair of cams, or two tandem pairs of cams.
 97. A methodfor clamping a plurality of circuit cards within a receptacle, themethod comprising: compressing axially at least one resilient elementbetween a head of a shaft and a nut disposed on the shaft so that the atleast one resilient element bulges generally perpendicularly to theaxial direction and into engagement with a frame within the receptacle,the frame partitioned into first and second subframes by a firstpartition, each of the first and second sub-frames partitioned into anarray of slots by a plurality of second partitions, each slot containingone of the circuit cards; exerting a force on the first sub-frame usingthe at least one resilient element; sliding the first sub-frame usingthe force exerted on the first sub-frame so that circuit cards of thefirst sub-frame contact the first partition; exerting a force on thefirst partition using the circuit cards of the first sub-frame; slidingthe first partition into contact with the circuit cards of the secondsub-frame using the force exerted on the first partition by the circuitcards of the first sub-frame; and securing the circuit cards containedin the slots of the first sub-frame between the first sub-frame and thefirst partition and the circuit cards contained in the slots of thesecond sub-frame between the first partition and the second sub-frame bymaintaining the force on the first sub-frame using the at least oneresilient element.
 98. The method of claim 97, and further comprisingattaching rotatably the shaft to the receptacle.
 99. The method of claim97, wherein compressing axially at least one resilient element comprisescompressing axially a pair of resilient elements between the head of theshaft and the nut.
 100. The method of claim 99, wherein compressingaxially a pair of resilient elements between the head of the shaft andthe nut comprises compressing one of the resilient elements between thehead and a sleeve and compressing the other resilient element betweenthe sleeve and the nut.
 101. The method of claim 97, wherein compressingaxially at least one resilient element comprises threading the shaftinto the nut.
 102. The method of claim 98, wherein attaching rotatablythe shaft to the receptacle comprises attaching the nut to thereceptacle.
 103. A method for clamping a plurality of circuit cardswithin a receptacle having first and second frames, each framepartitioned into first and second sub-frames by a first partition, eachof the first and second sub-frames partitioned into an array of slots bya plurality of second partitions, each slot containing one of thecircuit cards, the method comprising: attaching a shaft rotatably to thefirst sub-frame of the first frame between the first sub-frames of thefirst and second frames by disposing the shaft within a nut attached tothe first sub-frame of the first frame; compressing axially at least oneresilient element between a head of the shaft and the nut so that the atleast one resilient element bulges generally perpendicularly to theaxial direction and into engagement with the first sub-frame of thesecond frame; exerting a force on the first sub-frame of each of thefirst and second frames using the at least one resilient element;sliding the first sub-frame of each of the first and second frames usingthe force exerted on the first sub-frame of each of the first and secondframes so that circuit cards of the first sub-frame of each of the firstand second frames contact the first partition of each of the first andsecond frames; exerting a force on the first partition of each of thefirst and second frames using the circuit cards of the first sub-frameof each of the first and second frames; sliding the first partition ofeach of the first and second frames into contact with the circuit cardsof the second sub-frame of each of the first and second frames using theforce exerted on the first partition of each of the first and secondframes by the circuit cards of the first sub-frame of each of the firstand second frames; and securing the circuit cards contained in the slotsof the first sub-frame of each of the first and second frames betweenthe first sub-frame and the first partition of each of the first andsecond frames and the circuit cards contained in the slots of the secondsub-frame of each of the first and second frames between the firstpartition and the second sub-frame of each of the first and secondframes by maintaining the force on the first sub-frame of each of thefirst and second frames using the at least one resilient element. 104.The method of claim 103, wherein compressing axially at least oneresilient element comprises compressing axially a pair of resilientelements between the head of the shaft and the nut.
 105. The method ofclaim 104, wherein compressing axially a pair of resilient elementsbetween the head of the shaft and the nut comprises compressing one ofthe resilient elements between the head and a sleeve and compressing theother resilient element between the sleeve and the nut.
 106. The methodof claim 103, wherein compressing axially at least one resilient elementcomprises threading the shaft into the nut.